It is the long range purpose of this project to study the control mechanisms important in regulating cell growth, neoplastic transformation, and protein synthesis in normal and malignant lymphoid cells. To this end we are studying the structure of the genes for cellular oncogenes in normal and tumor tissues from mouse and man and the expression of these oncogenes as mRNAs. In particular we are focusing onthe B lymphocytic tumors of mice, plasmacytomas and lymphosarcomas, and we are investigating what role Abelson and Moloney leukemia viruses play in the induction of such tumors and the alteration of cellular oncogenes. We have discovered that increased expression of myc is found in all plasmacytomas, and that altered expression of myb is found in the lymphosarcomas. A morphologically distinct subset of lymphosarcomas has been shown to have altered myb mRNAs owing to the insertion of a deleted form of Moloney leukemia virus in the myb gene. This represents a mammalian example of oncogene activation by promoter/enhancer insertion of virus. We are also studying the expression of oncogenes in mouse and human autoimmune diseases. The study of the organization and expression of mouse and human IgD genes is continuing in mouse and human myelomas, with emphasis on cDNA and genomic cloning of the secreted and membrane forms of this immunoglobulin.